1. Field of the Invention
The invention relates to a cooled wall part, for example a wall part of flow-round hot turbomachine components, such as combustion chamber walls.
2. Discussion of Background
It is known, for the cooling of combustion chamber walls for the purpose of avoiding too high material temperatures, to employ convective cooling methods. Typically, in such methods, the cooling medium flows along, on the principle of cocurrent or countercurrent to the combustion chamber flow, in a cooling duct, located between the combustion chamber inner wall and combustion chamber outer wall. Alternatively, the cooling flow may be directed through an annular gap, or in separate cooling ducts delimited from one another. These convective cooling methods can be combined, for example, with impact cooling in order to produce high coefficients of heat transmission DE 2,836,539 C2.
Moreover, cooling techniques based on a controlled introduction of air into the combustion zone are known for the cooling of combustion chamber walls. This applies, for example, to film cooling, in which the cooling medium passes through orifices in the combustion chamber inner wall into the interior of the combustion chamber. The casting medium then flows along on the inside of the combustion chamber wall and there forms a thin film which constitutes a thermal insulating layer and which reduces the heat load on the wall.
These known cooling techniques scarcely any longer meet the constantly increasing requirements as to the efficiency of gas turbine plants, the extremely high temperatures associated therewith and the as low as possible cooling-air consumption.